HUTCHISON'S GAS AND WATER VALVE. Sir,-It has long been felt as a great desideratum by Gas and Water Companies that they should possess the most simple, and, at the same time, the most perfect valve for regulating the supply of gas or water. Hitherto all the valves that have been in use, owing to the complexity of their mechanism, the materials of which they are constructed, or both, have proved a source of considerable anxiety and disappointment to the superintendents of Gas and Water Establishments. Several ingenious inventions and improvements have from time to time been suggested and adopted, but all have more or less failed, or, at least, been only partially successful, causing great trouble and expense to the proprietors. en This has at last been obviated by Mr. Stephen Hutchison, the eminent gineer and patentee of the London GasWorks, in the construction of a valve, which for simplicity, correctness, and durability, stands unrivalled, and will, I have no doubt, be largely patronised. Its construction is so simple, that a boy of eight years of age can put it into action with the same certainty as the most scientific man; while, at the same time, its mechanism is adjusted to that nicely that the supply of gas or water can be regulated with the greatest precision. I am happy to be able to forward you a drawing and description of this most useful and ingenious machine. Fig. 1 represents the ordinary appearance of the machine as it stands in a room or office, showing the dial-plate, which is divided into thirteen parts or inches, from 1 to 12; the black space denoting when the valve is completely shut. It will be seen at once from the arrangement of the dial, that the greatest nicety can be obtained in regulating the supply of gas or water, alike avoiding a sudden pressure on the pipes, often causing accidents and that disagreeable jerk in gas lights so observable in some districts. aa, fig. 2, is a hollow shaft or column, through the centre of which passes b, an iron rod, with a screw or worm, having a square thread, as at c, and connected with the wheel d, which is made to revolve by means of a handle or crank e, affixed to the wheel f, also putting the wheel g in motion, through which is a 3 Sir,-In your 687th Number, I perceive a statement concerning an invention for alarmning poachers and thieves, instead of shooting thein with spring. guns or maining them with steel-traps. This consists in causing such persons to excite the firing of a rocket or other explosive contrivance, upon touching a wire or string, as was practised with springguns. I think I am entitled to state, that in this month (October) of last year, I ordered of Mr. Cannon, firework-maker, of the Westminster-road, certain parts of my contrivance for a precisely similar purpose, which I could not conveniently make at home; and explained to his wife the purpose to which I intended to apply them. According to my arrangement, rockets, petards, or any illuminating fires, may be left exposed to any rain or weather for any number of months, without deterioration, and the strings or wires may be laid on or taken off at pleasure. I have tried the plan, and have had two "flairups" in my little garden since I first applied it. I do not think I shall have a third-as the whole neighbourhood was alarmed, and the parties implicated could not conceal their feelings.-Yours, &c. F. MACERONI. Oct. 8, 1836. CHALKLEN AND BONHAM'S PATENT VICE. Sir,-The unequal wear and strain on the screw and shoulders of the common vice, render it so liable to break and get out of repair, that a simple and effectual remedy for those evils will be acknowledged by all who make use of it as a most valuable and important improve ment. Messrs. Chalklen and Bonham claim to have overcome these evils, by a very simple alteration in the present construction of the vice. Fig. 1. Fig. 2. B When the vice now in use (fig. 1) has any thing in it, and screwed up, the whole of the pressure is borne by the two points A and B, and of course the screw has a tendency to bend to the line m, and to throw all the strain on one part of the worm, &c.; hence arises the destruction of the worm, the bending of the screw, the wear of the shoulders, and in a short time the rice becomes completely out of order, which occasions the endless expense in large factories, where the work is heavy, of new boxes and screws every two or three weeks, besides a great difficulty to make them hold when opened wide. Messrs. Chalklen and Bonham's improvement is simply making the shoulders of the screw two hemispheres fitting into two sockets, A and B, fig. 2. Thus, in any situation of the vice, the force will always be uniformly distributed to all parts, and the direction of it remain in the centre of the screw if the greatest power be applied it cannot injure or have any tendency to bend. This is without doubt a very simple and important improvement in an apparatus used by almost every mechanic; and if it is found that the ball and socket does answer its end under a great degree of pressure (which appears doubtful), it will soon be extensively adopted. The Patentees have supplied a number to the Woolwich Dock-yard. There is another improvement in the vice which is a great desideratum, that is, a parallel motion. A BLACKSMITH. I am, &c. A PLAN WHEREBY A WOODEN RAILWAY SHALL BE RENDERED AS INDESTRUCTIBLE AS THE BEST IRON RAILROAD. (From the American Railroad Journal.) This plan consists in having the excavations and embankments made sufficiently wide to admit a side ditch, or ditches, and extra embankments raised upon the outer edges of the road to an elevation of fifteen or eighteen inches above the plane of the roadway. These extra embankments should be made about one foot wide on the top, with slopes of one and a half of hase to one of perpendicular rise. The side ditch or ditches with the extra embankments, and the upper surface of the roadway should be constructed with watertight materials, and the ditch or ditches made with the sufficient cross section to admit a quantity of water to feed the required distance. The cross section of the ditches will be greater upon the level parts of the road than on the descending planes, and greater at the end where the water is introduced, and decreasing toward the final discharge or waste of the water. The feeders should be admitted at conve nient distances, the less the distance from one feeder to another, the less will be required for the dimensions of the ditches. Waste weirs should be built at proper points, so as to discharge all surplus water, and the feeding gates should be regulated to give a certain quantity of water and no more, as near as the circumstances will admit. After the wooden sleepers and rails are laid, with the iron plate put on, and the road completed for use, the water should be introduced and maintained to an elevation that will completely cover the rails, leaving the track about one inch under water. will be a sufficient depth, and need not be exceeded for the purposes here required to accomplish. This It is well known that wood immersed completely under water is thereby prevented from decay, hence a wooden railroad in the situation here described would last as long as the best constructed iron road. The difference in cost of course would be different, as the circumstance and character of the ground would change; but I have no doubt but the average cost of railroad, upon this plan, would be 5000 dollars per mile less than the double track iron road. There is hardly any situation where railroads of any extent are made, but streams of water sufficient for the purposes required can easily be obtained. In the winter season the water should be drawn off or reduced at least two inches below the top of the rail. There is but little tendency to decomposition during the frosty weather, hence but little objection can be urged against this measure. The slight obstruction the water would be to the rapid progress of the engine and cars would be nearly balanced by having a constant clean and uniform surface for the wheels to run upon, the friction would be more equal, consequently the moving power could be better regulated. A thin light wooden box should be made to enclose the wheels from near their bearing surface over the top, in order to prevent the centrifugal force of the wheels in motion from throwing the water over the bodies of the engine, cars, &c. Many advantages might be enumerated in favour of this plan of making railroads. One is the uniformity which would be given to the temperature of iron plate, thereby correcting in a manner one of the great evils, the contraction and expansion of the iron plate. I believe, also, where a road should be made in this manner, and well settled, there would not be half the liability to derangement. It is the alternate wetting and drying causing the contraction and expansion of materials, which eventually disorganises the road. MINUTES OF EVIDENCE BEFORE A SELECT COMMITTEE OF THE HOUSE OF LORDS ON THE TOLLS ON STEAM CARRIAGES' BILL. SESSION 1836. [We gave in our last vol. p.335 the Report of the House of Lords Committee on the tolls on Steam Carriage Job, of Messrs. Goldsworthy Gurney and Co.; by which Report that very dirty job (to which this journal was the means of first calling public attention) was most happily frustrated. We now propose to select from the minutes of evidence taken on the occasion, whatever we can find of novelty or interest in them; passing over only such portions of it as consist of mere repetitions of facts and statements with which the scientific world is already familiar.-ED. M. M.] Mr. Goldsworthy Gurney Has had no engine on the road since 1831; before this period they ran a good deal in the neighbourhood of London. Went to Bath and came back in 1829. Carriages in 1830 were established between Gloucester and Cheltenham, and ran there uninterruptedly for four months, three times a day. They carried upwards of 4,000 persons over 5.000 and 6,000 miles of ground without any hurt or accident. And not running on that road now, because they were stopped by turnpike acts, which laid a toll of 11. each time of passing at both gates, a distance of eight miles, making 22s. for each journey. His carriage can be made to run round a circle of twenty feet diameter, at a speed of six or seven miles an hour.* Cannot say exactly how many miles his carriages have run along public roads; but should think 15,000 miles. Has not built an engine, nor had any one on the road since 1831. Thinks that if his carriages had gone on and been persevered in they would have prevented some of the railroads now in operation. Is quite satisfied of that. By a little experience and management, steam carriages will go nearly as fast and fully as safe on a common road as on a railroad. After a twelvemonth or two years observation the public would be satisfied with them, and a rapid rate would be permitted. It is rather a singular fact that when you are travelling at the rate of eighteon miles an hour in a steam carriage on a common road you are not sensible of the rapidity.+ Have you ever travelled eighteen miles an hour in a carriage on a common road?-Yes; I have gone eighteen miles within an hour. *??? + Very singular indeed; but should it not be added, after the manner of the Americans, if true. -Printer's Devil. From what place?-From Finchley to Regent's Park and back again twice, up the Highgate Tunnel. We travelled the first twenty-four miles in two hours in our journey to Bath. Have all the boilers tried on common roads been attended with loss of life, if constructed above a given size? I would not say that all have, but all I am acquainted with. What is the extreme size you would recommend?-The extreme size for public safety I am of opinion ought not to exceed eight or nine inches diameter. I think it essential to keep within that size; they may be reduced still lower. I am sure all en. gineers of experience would bear me out in stating that this size is sufficient for all purposes on common reads. The Committee are to understand that your carriage, though less in weight, has more power than the locomotive engines employed on railroads? Yes, compared to weight; on a railway they are very heavy. Have you heard of an instance which oc curred some two years ago of the gates on the Liverpool and Manchester railroad being carried off in the middle of the night?-I recollect hearing of the circumstance. Would such a thing occur with your carriage, if it were to come against a turnpike gate? It might possibly, by charging a turnpike gate with full steam, and carry it away; but a man must be mad to do it. Do you conceive your power is sufficient to do that under ordinary circumstances?—I think not. Have you heard of an instance of Mr. Hancock's engine striking the corner of a house? I was in the country at the time I heard of the circumstance, but I do not know whose carriage it was; I do not think it was Mr. Hancock's * I simply heard of a wall being driven in at Paddington. A great number of caricatures of steam carriages have certainly taken place; a great many undigested experiments have been made on the public roads, which have tended much to prejudice the public mind against the subject. What means do you propose for preventing the establishment of other caricatures, as you call them, of your project?-I think the toll being placed on the weight of the carriage will limit them in size. The clause in the bill subjecting them to double pres sure will be also another means; I think the clause limiting the size of the boiler will be the principal. Possibly, if the prohibitory The carriage which performed this exploit, was Messrs. Macerone and Squires'. tolls be taken off, and the subject be allowed to go on fairly, fair and legitimate carriages will alone be soon on the road. 'In what manner do you propose to guard against the introduction of other carriages further than as the weight would prevent their running with success?-The weight of the carriage would be only one guard, the proof to which the boiler is submitted would be a second, and the limited size of the boiler would be a third. Those are as much as I can point out capable of legislation. You were understood to state that there is no difficulty, however small the boiler, to raise the power of the engine?-- However small the vessels composing the boiler, you may with vessels not exceeding an inch in diameter obtain forty-horse power, or even one hundred-horse power. Do you suppose it would not answer for an individual to undertake to draw a train weighing twenty or thirty tons to pay a toll upon them?-In the first place, I think it would not be practicable to do it; secondly, the expense would be very considerably more than horses; for when we exceed a given relative weight the expense of steam becomes greater than that of horses. Can you state what that limit is ?-If I speak in engineer's terms, a horse power boiler should not exceed three hundred weight; if it exceeds this weight it becomes far more expensive than horses. If you could have, without increasing the size of the boiler, a forty horse power engine, it is perfectly evident you could carry three times forty hundred weight?-I think I am misunderstood. In regard to pressure, I have been speaking of the separate vessels composing the boiler; if one vessel will generate steam enough for a horse power, then it will require two for a two-horse power. you require a forty horse power, you must have forty vessels, each vessel or series representing a horse power. The boiler for producing steam sufficient for a horse power must be practically under three hundred weight. If In your engine for every horse power you would have a distinct boiler?-For every horse power there is a given number of those tubes, increasing in direct ratio as the horse power is increased; so the number of those must always be increased in that ratio. You were understood to say you could increase the pressure on your boiler to any given extent?-Certainly. The tubes when formed together compose the boiler as a whole; every tube will bear the same pressure. You were understood to have stated that a boiler could bear pressure to a hundred atmospheres?—I said it was capable of almost unlimited resistance. How would you restrain any individual from making a pressure on a given tube of above one-horse power?-I hardly understand the question. If he was to double the pressure upon a tube, the power of the engine would be increased. This is a question more of force or intensity than a question of power. Series of tubes would work the engine under the power of one hundred to an inch, or at fifty; the rate would determine the power. What is gained in power may be lost in time. The actual power is represented by the quantity of steam, not by the pressure. Your steam carriages are totally inapplicable for merchandise?-Quite so; only for passengers and quick travelling. With how many carriages in their train? -Not more than one. You can go, you say, at the rate of eighteen miles an hour?-Certainly it can be done, but the best practical rate is from twelve to fourteen. How soon after the new tolls were imposed did you give up running between Gloucester and Cheltenham ?--Not till they were imposed. How soon after? Directly. Did you find it a profitable speculation? -The speculation belonged to Sir Charles Dance; he was the proprietor of the carriage; and the speculation was his. It appears from the accounts of expenditure and return that there must have been a considerable profit. You considered it a profitable undertaking? Yes. I have a letter of Sir Charles Dance's, in which he states it himself. Can you say why Sir Charles Dance did not try running in the neighbourhood of London, where there were no such tolls?After he returned from Gloucester he became acquainted with Messrs. Maudslay and Field, the great practical engineers; they made alterations in the carriage, with a view of improving it. Experiments were made after that by Sir Charles Dance and Mr. Field, to determine the value of these alterations; but they never ran, nor did Sir Charles intend to run till we could get the question of tolls settled; it was not the particular road on which the tolls were laid then that stopped us, but the fact that wherever we attempted to run, or contracts were made, we were met by an Act of Parliament. Was there any instance of an act being passed except where some great improvement took place on the road, or the existing act had expired? I cannot answer that question as to the cause directly which occa sioned acts to pass; but this I can state, that on the great line of road between London and Liverpool, Liverpool and Edinburgh, which were contracted for, the turnpike tolls were laid; also between Glasgow and Edinburgh. |